Author
Nicolas Alejandro Salinas
nico.salinas95@gmail.com
Fundación para el Estudio de Especies Invasivas (FuEDEI)
Hurlingham
Coauthors
Daniel Poveda-Martínez, Centre de Biologie pour la Gestion des Populations (CBGP-IRD), Montpellier, France
Melissa C Smith, USDA-ARS Invasive Plant Research Laboratory, Fort Lauderdale, USA
Julie A Coetzee, Centre for Biological Control, Rhodes University, Makhanda, South Africa
Martin P Hill, Centre for Biological Control, Rhodes University, Makhanda, South Africa
Marcela S Rodriguero, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
María E Brentassi, División Entomología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata, Argentina
Alejandro J Sosa, Fundación para el Estudio de Especies Invasivas (FuEDEI), Hurlingham, Argentina
Abstract
Megamelus scutellaris (Hemiptera: Delphacidae) is a monophagous insect used as a biocontrol agent against water hyacinth (Pontederia crassipes). While it has shown success in reducing plant densities, differences in its field performance have been observed, potentially influenced by the genetic background of the source populations and post-introduction evolutionary processes. In this work, we used nuclear SNP data to investigate the genetic structure, demographic history, and environmental drivers of population divergence in M. scutellaris across its native range in Argentina as well as in its introduced populations. Our main results reveal three main genetic lineages in the native range, broadly corresponding to major ecoregions and river basins, with evidence of contemporary asymmetric gene flow among them. Moreover, landscape genetic analyses indicate that genetic differentiation is significantly associated with climatic factors. On the other hand, introduced populations in the US and South Africa show genetic differentiation from their source populations, particularly pronounced in South Africa. Insights into the genetic structure and evolutionary history of M. scutellaris can both inform the selection of source populations and elucidate how post-introduction processes may affect long-term biocontrol outcomes.
keywords
Genomics
Biocontrol improvement
Post-release comparisons
Demographic modelling
Landscape genomics
Highlights
Assessing native genetic structure can inform the selection of biocontrol agent source populations.
Climate plays a key role in shaping genetic differentiation of M. scutellaris.
Megamelus scutellaris introduced populations undergo post-release genetic shifts.